During Gao Jian's tenure as mayor, Seoul successfully hosted the 1988 Seoul Olympic Games. The proper management of Gao Jian made the Olympic Games famous for South Korea internationally. Therefore, he is called "Mr. Stability" and "Master of Administration" by Koreans. In 2002, it co-hosted the World Cup with Japan. What the Korean people praise most is that he turned the former garbage mountain in Seoul into an "environmental protection green park" and built a new "Seoul Shangyandong World Cup main stadium".

Gao Jian often uses his motto-"A wise man is honest" to push himself. 1998, Gao Jian launched an "online civil application procedure strengthening system" to improve the efficiency and transparency of the municipal government and prevent government civil servants from asking for bribes. This system has greatly reduced the corruption among civil servants in Seoul city government, and Gao Jian was elected as the chairman of South Korea's "National Anti-Corruption Federation". In 200 1 year, Transparency International awarded him the World Corruption Prevention Award.

Gao Jian went to Beijing to attend the World Metropolis Summit in September 2000.

Both Gao Jian and Roh Moo-hyun belong to the New Millennium Democratic Party.